@samuel-serrano

Welcome to the Magix user to user forums.

First, please read this post and give us ALL the information requested there.

Then , please tell us exactly which version and build of MEP you have (you can check under Help>About) and which variant, Basic, Plus or Premium.

Then, because mp4 is a container format and can involve a whole range of different codecs, please download and install the free MediaInfo utility, point it to your file which you cannot play and then post the results of the Text view here.

Basically, most types of mp4 file should play without problem in MEP but this cannot be guaranteed, so please help us to help you by giving us all the details I've asked for.

Jeff
Forum Moderator